The present invention relates to a stapler wherein the force that ejects staples can be adjustable.
A conventional stapler generally includes a casing with a push type handle which is cooperated with a resilient member which is deformed to store energy when the handle is pushed. The resilient member is linked with an ejection device which is moved at a speed by the energy of the resilient member when the handle is disengaged from the resilient member by pushing the handle to a position. The ejection device ejects a staple via a guide member of the stapler and the staple staples sheet of document together. However, the staples are urged by a spring in the stapler so as to feed the following staples to the position to be ejected. It could be dangerous when the user put new staples from a front end of the stapler because the staples could be bounced by the spring. The ejection device is sealed in the casing of the stapler so that it is difficult for the users to maintain the ejection device which will be worn out. The ejection force of the stapler cannot be adjusted.
In accordance with one aspect of the present invention, there is provided a stapler which comprises a casing having a grasp hole defined therethrough and a staple receiving frame is received in the casing. A staple pushing device is engaged with the frame and includes a push plate slidably mounted to the staple receiving frame. A groove is defined in a periphery of the grasp hole and a pressing rod is movably engaged with the groove. Two resilient plates each have an end fixedly connected to the casing and the pressing rod presses on the resilient plates. A horizontal plate is located in the casing and has two slots. A staple ejection device is connected to the casing and has a base plate and an ejection plate. The base plate and the ejection plate both are connected to the resilient plates. A handle is pivotally connected to the casing and disengagably connected to the staple ejection device. An outer cover is mounted to the casing and a front cover is connected to the casino and mounted to the outer cover. The front cover has a guide member and a grasp member which is pivotally connected to the guide member. The guide member has two hooks which are engaged with the two slots of the horizontal plate in the casing. The grasp member is engaged onto the outer casing.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show. for purposes of illustration only, a preferred embodiment in accordance with the present invention.